#!/usr/bin/env bash
#
# unstage the selected staged file
# or reset the commit to certain point
#
# @params
# Globals
#   ${mydir}: current directory of the script
#   ${reset_type}: reset type, modified files, all files or commit
#   ${reset_option}: git reset flag, --mixed | --soft | --hard
#   ${selected_files}: selected file to unstage
#   ${selected_commit}: selected commit to reset
#   ${confirm}: confirmation status of the user
# Arguments
#   -h: show help message and quit
#   -a: select files and select a commit to reset the fiel back to selected commit
#   -c: reset commit
#   -S: use --soft flag
#   -H: use --hard flag
#   -y: confirm action by default and skip confirmation

set -e
set -f

mydir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
source "${mydir}"/../helper/set_variable.sh
source "${mydir}"/../helper/get_confirmation.sh
source "${mydir}"/../helper/git_query.sh

function usage() {
  echo -e "Usage: dotbare freset [-h] [-a] [-c] [-S] [-H] ...\n"
  echo -e "Reset/Unstage the selected staged file"
  echo -e "Or reset the HEAD to certain commits by using -c flag\n"
  echo -e "Default: unstage the selected files from\n"
  echo -e "optional arguments:"
  echo -e "  -h\t\tshow this help message and exit"
  echo -e "  -c\t\treset commit to certain commit, default --mixed flag, reset HEAD to certain commit put all changes into modified states"
  echo -e "  -S\t\treset commit using --soft flag, reset HEAD to certain commit without modify working tree"
  echo -e "  -H\t\treset commit using --hard flag, reset HEAD to certain commit dicard all changes from the working tree"
  echo -e "  -y\t\tconfirm action by default and skip confirmation"
}

reset_option="--mixed"
reset_type="modified"
selected_files=()

while getopts ":hacSHy" opt
do
  case "$opt" in
    c)
      reset_type="commit"
      ;;
    S)
      reset_option="--soft"
      ;;
    H)
      reset_option="--hard"
      ;;
    y)
      confirm='y'
      ;;
    h)
      usage
      exit 0
      ;;
    *) 
      echo "Invalid option: ${OPTARG}" >&2
      usage
      exit 1
      ;;
  esac
done

if [[ "${reset_type}" == "commit" ]]; then
  selected_commit=$(get_commit)
  [[ -z "${selected_commit}" ]] && exit 0
  [[ -z "${confirm}" ]] && confirm=$(get_confirmation "Reset HEAD to ${selected_commit} ${reset_option}?")
  [[ "${confirm}" != 'y' ]] && exit 1
  /usr/bin/git --git-dir="${DOTBARE_DIR}" --work-tree="${DOTBARE_TREE}" reset "${selected_commit}" "${reset_option}"
else
  while IFS= read -r line; do
    selected_files+=("${line}")
  done < <(get_modified_file 'select files to unstage' 'staged')
  [[ "${#selected_files}" -eq 0 ]] && exit 1
  /usr/bin/git --git-dir="${DOTBARE_DIR}" --work-tree="${DOTBARE_TREE}" reset HEAD "${selected_files[@]}"
fi